1. Field of the Invention
This invention relates generally to methods of and apparatus for lining the internal walls of a conduit, and in particular it relates to methods of and apparatus for lining the internal walls of a conduit for conveying fluid carrying marine fouling organisms with anti-fouling material for preventing such marine fouling organisms from contacting the internal conduit walls and thereby from adhering thereto and constricting the flow of fluid through the conduit.
2. Description of the Prior Art
As is known to those skilled in the marine art, marine fouling organisms will eventually adhere to or collect on the surface of any object exposed to the sea water. Such marine fouling organisms include all marine growth capable of forming a more or less secure attachment to a surface exposed thereto, or which contribute a more or less adherent deposit to a surface exposed thereto. Marine fouling organisms can be divided into two groups, namely the group of uni-cellular micro-organisms composed of many species of bacteria and other plant life, and various types of protozoa, and the group of macro- or multi-cellular organisms, both plant and animal. Such marine fouling organisms include practically all of the marine bacteria, flora, invertebrate fauna present in sea water and especially include barnacles and other marine crustaceans found in sea water.
As further known to those skilled in the marine art, sea water is used as a coolant for steam condensers utilized in electrical generating plants. The sea water is conveyed to and from the condensers by large diameter concrete pipes or conduits. Over a relatively short period of time, marine fouling organisms carried by the sea water adhere to or collect on the internal walls of the concrete pipes and constrict the flow of sea water through the pipes so severely that the electrical generating plant must be closed down for an extended period of time sufficient to permit the internal walls of the pipes to be mechanically cleaned such as by scraping and/or air blasting. Since this cleaning operation results in the electrical generating plant being shut down, it is enormously expensive and highly undesirable.
Various anti-fouling materials are known to the art which are capable of preventing marine fouling organisms from contacting the surface protected by the liner and to which marine life does not substantially adhere. Such known anti-fouling materials include copper and various copper base alloys.
As reported in the reprint from POWER ENGINEERING MAGAZINE entitled, "Special Linings In Concrete Intakes Prevent Fouling From Marine Growth," authored by Harold A. Todhunter, Mechanical Design Engineer, Los Angeles Dep-. of Water and Power, and which reprint is provided by the International Nickel Co., Inc., 67 Wall Street, N.Y., N.Y. 10005, sheets of anti-fouling material, for test purposes, have been nailed to the walls of a concrete intake to prevent fouling of the intake walls by marine growth. The anti-fouling material used was a copper base alloy, viz., a 90 -10 copper-nickel alloy, and the nails used were Inconel 750X nails installed with Ramset guns. Obviously, such installation of anti-fouling material requires that the concrete intake be drained and equally obvious is that such an installation would be undesirably time consuming and enormously expensive if used in conjunction with an operating electrical generating plant because it would require the electrical generating plant to be shut down during installation.
Accordingly, there exists a need in the art of an anti-fouling liner which may be readily and relatively inexpensively inserted inside of a conduit, e.g. a sea water conveying conduit, and which liner has the capability of being inserted into the conduit while the sea water is still present although the flow of sea water through the conduit may have to be temporarily halted or slowed. Thus, even if an associated electrical generating plant must be shut down, the shut down would be only quite temporary and of a much shorter duration than required by the above-noted prior art.